I did a hard reset and I am trying to unlock it with the code via the phone dialpad, but I cannot get the "P", "W" or "+" characters to appear. The instructions say...

The letter p appears if you press the button star(*) three times quickly
The letter w appears if you press the button star(*) four times quickly
The symbol + appears if you press the button star(*) two times quickly

...but it doesn't work. If I press * 3 times quickly I get 3 stars. And I have tried it at all varying degrees of "quickly". I must be msising something...

If I were you I wouldn't mess up with the ROM's (Builds) as AT&T's builds are different from generic builds. Why not ask someone else's sim (must be an AT&T with a data plan on it) to check?

I can make a custom wallpaper for you for no cost :) just hit me up & check my wallpaper thread - hereMy Comic Book - Its about Iphone 5s and Innovation Click here